Portable sanding machine



April 2, 1929, v H. A. SWAN 1,707,584

PORTABLE SANDI NG' MACHINE File d Sept. 29, 1927 5 Sheets-Sheet 1 Wflaw/7 if 6294/7, INVENTOR.

/ 0&5'666 ATTbRNEs s.

April 2, 1929. H. A. SWAN 1,707,584

PORTABLE SANDING MACHINE Filed Spc. 29, 1927 3 Sheets-Sheet 2 ATTORNEYS.

April 2, 1929.

/ V/ fnesaea H. A. SWAN 1,707,584

PORTABLE S ANDI NG MACHI NE Filed Sept. 29', 1927 s Sheets-Sheet 5f/d/fa/a' 67040; INVENTOR.

A TTORNEYS.

Patented Apr. 2, 1 929.

UNITED STATES lEAROLD A. SWAN, OF CORONADO, CALIFORNIA.

PORTABLE SANDING MACHINE.

Application filed September 29, 1927. Serial No. 222,8.

This invention relates to improvements in sanding machines and has asits general object to provide a machine which will be highly efficientin operation and whichwill operate to abrade or sand the work to bedressed, in a highly eflicient manner and with the expenditure of muchless time than is ordinarily required in performing this task.

Another object of; the invention is to provide a sanding machine ofcompact construction and operated through the medium of an electricmotor, the machine being adapted to be conveniently manipulated andguided over the surface of the work to be dressed.

Another object of the invention is to provide a sanding machine whichmay be readily converted for use either by the employment of an endlessbelt as-the abrading medium, or by utilizing one of the rolls over whichthe belt is trained and by which it is driven, as the abrading means, sothat the machine may be conveniently and readily converted from a beltsander to a cylinder sander, and vice versa, depending upon thecharacter of the .2 work.

Another object of the invention isto provide novel means fortransmitting power to the abrading element of the machine, whether it bea belt, or one of the rolls about which the belt is trained and fromwhich the belt is driven.

Another object of the invention is to provide novel means formaintaining the lower or working stretch o'tthe abrading belt in fiatand even contact with the surface of the work to be dressed, Where thebelt is employed as the abrading medium, and to provide for utilizationof this means as a means for steadying and supportingthe machine formovement over the surface of the work, when the belt is removed and thedrive or power roll of the machine is employed as the abrading medium.

While the accompanying drawings and the description which is to follow,constitutea disclosure of the preferred embodiment of the invention, itwill be understood that various changes may be made within the scope ofwhat is claimed. i

In the accompanying drawings: .Fig. 1 is a side elevation of the sandingmachine embodying the invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a vertical longitudinal sectional view through the machine;Fig. 4 is a vertical transverse sectional view taken substantially onthe line 4-4 of Figure 3 looking in the direction indicated by thearrows;

Fig. 5 is a similar view on the line 55 of Figure 3 looking in thedirection indicated by the arrows;

Fig. 6 is a vertical transverse sectional view taken substantially onthe line 6-6 of Figure 1 looking in the direction indicated by thearrows;

Fig. 7 is a front elevation of the machine, a part being shown insection.

The machine embodying the invention includes a body casting whichincludes a base 1, an electric motor casing 2 which is integral with thebase 1 and located substantially at the center of the upper sidethereof, and a gear case 3 which is likewise cast integral with the baseand located at the rear. thereof and in rear of the motor casing 2. Theelectric motor of which the casing 2 constitutes a part, is of anyapproved type, and the conductor wires for the motor, indicated by thenumeral 4, are led to the motor through the forward side of the casing2, from any suitable source of current supply. Ears 5 are formedintegrally with the oppositesidesof the base 1 at the rear end thereof,and a' spindle 6 is fitted through bosses 7 formed upon the inner sidesof the ears and threaded at one end as'at 8 into one out the saidbosses. A sleeve 9 is fitted onto the said spindle for rotation andsupports the drive or ower roll of the machine which is indicated y thenumcral 10. The under side of the base 1 isrecessed at the forward endof the base as indicated by the numeral 11, and a bearing membercomprising a plate 12, is slidably adjustably disposed within the recessand is adapted to be adjusted in a forward and rearward direetionthrough the medium (if a screw 13 having right and left hand threads,one end of the screw being threaded into an opening 14 formed in anupstanding lug 15 formed inte ral with the upper side of the base 1, theot er end of the screw being threaded through an opening 16 formed in ancar 17 upstanding from the plate 12 at the forward slde of the saidplate, the said ear 17 working in a slot 18 formed to extend in a frontto rear direc tion longitudinally within the said base 1 at the upperside and front of the recess 11 therein. Ears 19 project downwardly fromthe opposite ends of the plate 12, and a spindle 20 corresponding to thespindle 6, is mounted at its ends in the said cars 13 and has rotatablyfitted thereon a sleeve 21 which supports a roll which is indicated bythe numeral 22 and which is of the same dimensions as the roll 10. Abelt 23 is trained over the rolls 1() and 22 with its upper stretchtravelling beneath the base 1 and its lower stretch travelling beneath ashoe which is adjustably mounted beneath the base 1 as will presently beexplained, it being understood at this point that the belt may berendered taut by adjusting the screw 13 so as to move the bearing member12 in a forward direction, the screw being provided between its threadedend portions, with a knurled head 24: to facilitate such adjustment ofthe screw.

The belt 23 will have applied to its outer surface, a coating of anysuitable abrading material such for example as sand or garnet, and itwill readily be understood that the lower stretch of the beltconstitutesthe abrading stretch.

In order that motion may be imparted to the belt 23, means is providedwhich will now be described.

The means referred to above comprises a shaft 25 which is rotatablyjournaled. at its ends in suitable bearings 26 upon the opposite sidewalls of the gear case 3, and this shaft has fixed upon it, midwaybetween its ends, a worm gear 27 which is in mesh with a worm 28 fixedupon the shaft 2 9 of the motor 2, the motor shaft having its rear endextended longitudinally through the gear casin 3 and journaled insuitable hearings in said casing. Wheels 30 are fixed upon the shaft 25at the under sides of the worm gear 27 and each of these wheels isprovided with a rim 31 which is preferably of soft rubber and preferablyformed with a number of concave depressions 32 in its surface. As willbe observed by reference to Figures 3 and 6 of the drawings, the rims 31of the wheels 30 travel in frictional contact with the portion of thebelt 23 which passes over the upper side of the roll 10 and in thismanner motion is transmitted to the belt and roll, so as to effecttravel of the belt and cause the lower stretch thereof to act upon thepiece of work to be dressed. It will be evident that inasmuch. as therim 31 of each wheel 30 is of soft rubber and is formed with thedepressions 32, these depressions constitute, in edect, vacuum cupswhich insure of a positive and steady appli cation of power through themedium ofthe rim 31, to the belt 23, and likewise the cups serve toremove particles of material which might otherwise adhere to the surfaceof the menace belt, and which particles are removed by the abrasiveaction of the lower stretch of the belt upon the surface of the work.Therefore the wheels 30 and their rims 31 constitute not only means fortransmitting motion to the belt, but also as a means for freeing thebelt from accumulations which would be liable to impair its efiiciencyas an abrading medium,

In order that the lower stretch ofthe belt 23 may be held in snug andflat contact with the surface of the work to be dressed, means isprovided for backing this stretch of the belt or in other words forholding it against upward flexing or displacement, and this meansincludes a shoe which is indicated in general by the numeral 33 andcomprises a body plate 3% to the under side of which there is appliedand suitably secured, by adhesive or otherwise, a sheet 35 of felt orother material found suitable for the purpose. The plate 3a is of oblongrectangular form and, as will be observed by reference to Figures 1, 3,4 and 5. extends in a front to rear direction in the space between therolls 10 and 22 and is of a width slightly greater than the width of thebelt 23, the lower stretch of the belt traveling beneath the shoe and incontact at its upper surface with the under surface of the sheet 35, asclearlyshown in Figures 3, a and 5 of the drawings. It will be observedat this point that the under surface of the sheet 35 of the shoe 33occupies the same horizontal plane as'the under sides of the rolls 10and 22, so that the lower stretch of the belt 23 is not only held tautthrough adjustment of the screw 13 and the conseguent adjustment of theroll 22 in a forwardirection and away from the roll 10, but also byreason of the engagement of this stretch against the sheet '35 which isrendered substantially rigid through its attachment to the plate 34..The plate 34 has formed upon its 7 upper side, near its forward end, apair of upstanding lugs 36 the upper sides of which" iio are inclineddownwardly and forwardly and provided with laterally outstanding tongues37 which tongues work in grooves 38 provided between spaced ribs 39formed upon the inner sides of depending side portions or check pieces40 which are integral with the base 1 and project downwardly therefromas clearly shown in Figures 1, 3 and 4 of the drawings. Lugs 41 similarto the lugs 33 are formed upon the plate 34 near the rear end thereofand are rovided with outstanding tongues 42 whlch'are inclineddownwardly as in the case of the tongues. 37 and are guided in grooves43 formed between spaced ribs 44- in turn formed upon the inner sides ofcheek pieces 1-5 which correspond to the cheek pieces 40, previouslydescribed and which therefore, as in the case of the said cheek pieces40, depend from the opposite sides of the base 1. A pair of ears 46 isformed upon the upper side of the plate 34 near the front thereof andbetween the lugs 36, and a bearing block 47 is swingingly mounted upon arivet 48 which extends be-" tween the cars 46, and is provided with athreaded openlng 49 into which is adjustably threaded the forwardportion of a stem 50,

adapted to accommodate the end of a nail or any other pointed devicewhereby the head ,may be rotatably adjusted to correspondingly adjustthe stem 50. The stem extends likewise rearwardlybeyond the head, 51 andthis portion 'of the stem, at its extremlty, is

.rotatably fitted in an opening 53 formed in an car 54 which dependsfrom the under side of a collar 55 which is pressed or otherwise securedupon a-sleeve 56' which is rotatably fitted on a bolt 57; which is.inserted through anopening in one of the cheek pieces 45 and threaded atits end into an opening in the other cheek The end of the stem 50 whichis rotatably mounted in the opening 53, is provided with spaced collars58 which engage the front and. rear sides of the ear54 s0 as to preventlongitudinal displacement of the said end of the stem 50 in the openingin the said ear and'yet provide for free rotative adjustment of the stemso as to effect longitudinal adjustment of the bearing block 47 andthus, in turn, effect a forward or rearward adust-ment of the plate ofthe backing mem er or shoe 33. At this pointit will be understood thatwhen the shoe 33 is adjusted forwardly, the tongues 37 and 42' ridingdownwardl inand being guided by-the grooves 38 and 43, respectively,will effect a downward displacement of the shoe 33, whereas a reverseadjustment of the shoe will result in elevation of the shoe. Thereforethe screw stem 50 may be adjusted so as to effect adjustment of the shoeto cause the same to more 'or less firmly bear against the upper side ofthe lower stretch of the belt 23 and thus maintain this stretch of thebelt flat and prevent upward sagging or distortion thereof when thelower or abrading side of the stretch is disposed upon-thelsurface ofthe work to be dressed. I

From the foregoing description of this embodiment of the invention itwill be evident that there has been provided a sanding machine which isextremely simple and compact in its construction and which maybe veryconveniently employed in dressing work and in a manner to effect sandingof work more expeditiously than can, be done by hand or by the use ofother machines which do not possess the features of the present machine.

V In. the embodiment of the invention illustrated an described, travelis imparted to the belt 23 through direct contact of the yieldwiseaccumulate upon the abrading surface of the belt will beremoved bysuction.

Under some conditions it may be desirable, due to the character of thework to be dressed, or ot er conditions met with, to abrade the surfa eof the work through the medium of a rot ry, roll rather than through thepassage of the stretch of an abrading-belt over the work, and thepresent invention is peculiarly adapted to this adaptation of themachine illustrated inasmuch as, in such event, it is only necessary toremove the front roll 22 and belt 23, and apply a sheet of abrasivematerial about the surface of the roll- 10, whereupon the machine ma bemoved over the surface of the work to. e dressed in the same manner asthough the belt were present, the roll, in this instance, acting uponthesurface to dress the same, and the shoe 33 serving as a support for themachine so as to properly position the roll with respect to the surfaceof the work.

. Having thus described the invention, what shaft and having ayieldable, cupped rim in frictional driving contact with the abradingmedium.

2. In an abrading machine of the glass described, a body, an abradingmedium opera-,

tivel mounted thereon, a power shaft upon the ody, a wheel driven fromthe power shaft, and a rim of yieldable friction mate-- rial upon thewheel in direct frictional driving contact with the abrading medium, thesaid rim having depressions in its friction surface for enhancing thefrictional contact between the rimtand the said abrading medium an forremoving accumulations from the surface of the said medium through 5110-tion created, by compression'and expansion of the depression bearingportion of the rim.

3. In an abrading machine of the class described, a body, an abradingmedium operatively mounted thereon, a motor mounted upon the body, ashaft mounted upon the body counter to the shaft of the motor, a gearupon the second mentioned shaft, a gear element upon the motor shaftcoacting with the gear uponthe second mentioned shaft, and spacedfriction wheels upon the second mentioned shaft having yieldable rims indirect about the rolls, means for adjusting the last frictional drivingContact With the ab'rading mentioned roll, and friction means upon the 1medium. body having frictional driving contact with 4. In an abradingmachine of the class dethe said abrading medium at its portion 5scribed, abody, aroll rotatably mounted upon which is in engagement withthe first menthe body, a second roll rotatably mounted tioned roll. uponthe body in spaced relation to the first In testimony whereof I affix mysignature. mentioned roll, an abrading belt trained HAROLD A. SWAN.

